[FFmpeg-devel] [PATCH] libavcodec/sanm: SMUSH codec48 decoder
Marton Balint
cus at passwd.hu
Fri Jan 3 00:53:21 EET 2025
On Thu, 2 Jan 2025, Manuel Lauss wrote:
> Hello,
>
> Ping? With this patch the 2 sample files at
> http://samples.mplayerhq.hu/game-formats/la-san/jediknight-sith/ play
> just fine.
Will apply.
Thanks,
Marton
>
> Thanks,
> Manuel
>
> On Mon, Dec 16, 2024 at 5:08 PM Manuel Lauss <manuel.lauss at gmail.com> wrote:
>>
>> Adds a decoder for the SMUSH codec48 video encoding, as is used by
>> the LucasArts game "Mysteries of the Sith".
>>
>> Signed-off-by: Manuel Lauss <manuel.lauss at gmail.com>
>> ---
>> libavcodec/sanm.c | 223 ++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 223 insertions(+)
>>
>> diff --git a/libavcodec/sanm.c b/libavcodec/sanm.c
>> index 8bcffb1e90..a278ef24b1 100644
>> --- a/libavcodec/sanm.c
>> +++ b/libavcodec/sanm.c
>> @@ -995,6 +995,227 @@ static int old_codec47(SANMVideoContext *ctx, int top,
>> return 0;
>> }
>>
>> +// scale 4x4 input block to an 8x8 output block
>> +static void c48_4to8(uint8_t *dst, const uint8_t *src, const uint16_t w)
>> +{
>> + uint16_t p;
>> + // dst is always at least 16bit aligned
>> + for (int i = 0; i < 4; i++) {
>> + for (int j = 0; j < 8; j += 2) {
>> + p = *src++;
>> + p = (p << 8) | p;
>> + *((uint16_t *)(dst + w * 0 + j)) = p;
>> + *((uint16_t *)(dst + w * 1 + j)) = p;
>> + }
>> + dst += w * 2;
>> + }
>> +}
>> +
>> +static int codec48_block(SANMVideoContext *ctx, uint8_t *dst, uint8_t *db,
>> + const uint16_t w)
>> +{
>> + uint8_t opc, sb[16];
>> + int i, j, k, l;
>> + int16_t mvofs;
>> + uint32_t ofs;
>> +
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 1)
>> + return 1;
>> +
>> + opc = bytestream2_get_byteu(&ctx->gb);
>> + switch (opc) {
>> + case 0xFF: // 1x1 -> 8x8 block scale
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 1)
>> + return 1;
>> +
>> + opc = bytestream2_get_byteu(&ctx->gb);
>> + for (i = 0; i < 16; i++)
>> + sb[i] = opc;
>> + c48_4to8(dst, sb, w);
>> + break;
>> + case 0xFE: // 1x 8x8 copy from deltabuf, 16bit mv from source
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 2)
>> + return 1;
>> + mvofs = bytestream2_get_le16(&ctx->gb);
>> + for (i = 0; i < 8; i++) {
>> + ofs = w * i;
>> + for (k = 0; k < 8; k++)
>> + *(dst + ofs + k) = *(db + ofs + k + mvofs);
>> + }
>> + break;
>> + case 0xFD: // 2x2 -> 8x8 block scale
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 4)
>> + return 1;
>> + sb[ 5] = bytestream2_get_byteu(&ctx->gb);
>> + sb[ 7] = bytestream2_get_byteu(&ctx->gb);
>> + sb[13] = bytestream2_get_byteu(&ctx->gb);
>> + sb[15] = bytestream2_get_byteu(&ctx->gb);
>> +
>> + sb[0] = sb[1] = sb[4] = sb[5];
>> + sb[2] = sb[3] = sb[6] = sb[7];
>> + sb[8] = sb[9] = sb[12] = sb[13];
>> + sb[10] = sb[11] = sb[14] = sb[15];
>> + c48_4to8(dst, sb, w);
>> + break;
>> + case 0xFC: // 4x copy 4x4 block, per-block c37_mv from source
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 4)
>> + return 1;
>> + for (i = 0; i < 8; i += 4) {
>> + for (k = 0; k < 8; k += 4) {
>> + opc = bytestream2_get_byteu(&ctx->gb);
>> + mvofs = c37_mv[opc * 2] + (c37_mv[opc * 2 + 1] * w);
>> + for (j = 0; j < 4; j++) {
>> + ofs = (w * (j + i)) + k;
>> + for (l = 0; l < 4; l++)
>> + *(dst + ofs + l) = *(db + ofs + l + mvofs);
>> + }
>> + }
>> + }
>> + break;
>> + case 0xFB: // Copy 4x 4x4 blocks, per-block mv from source
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 8)
>> + return 1;
>> + for (i = 0; i < 8; i += 4) {
>> + for (k = 0; k < 8; k += 4) {
>> + mvofs = bytestream2_get_le16(&ctx->gb);
>> + for (j = 0; j < 4; j++) {
>> + ofs = (w * (j + i)) + k;
>> + for (l = 0; l < 4; l++)
>> + *(dst + ofs + l) = *(db + ofs + l + mvofs);
>> + }
>> + }
>> + }
>> + break;
>> + case 0xFA: // scale 4x4 input block to 8x8 dest block
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 16)
>> + return 1;
>> + bytestream2_get_bufferu(&ctx->gb, sb, 16);
>> + c48_4to8(dst, sb, w);
>> + break;
>> + case 0xF9: // 16x 2x2 copy from delta, per-block c37_mv from source
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 16)
>> + return 1;
>> + for (i = 0; i < 8; i += 2) {
>> + for (j = 0; j < 8; j += 2) {
>> + ofs = (w * i) + j;
>> + opc = bytestream2_get_byteu(&ctx->gb);
>> + mvofs = c37_mv[opc * 2] + (c37_mv[opc * 2 + 1] * w);
>> + for (l = 0; l < 2; l++) {
>> + *(dst + ofs + l + 0) = *(db + ofs + l + 0 + mvofs);
>> + *(dst + ofs + l + w) = *(db + ofs + l + w + mvofs);
>> + }
>> + }
>> + }
>> + break;
>> + case 0xF8: // 16x 2x2 blocks copy, 16bit mv from source
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 32)
>> + return 1;
>> + for (i = 0; i < 8; i += 2) {
>> + for (j = 0; j < 8; j += 2) {
>> + ofs = w * i + j;
>> + mvofs = bytestream2_get_le16(&ctx->gb);
>> + for (l = 0; l < 2; l++) {
>> + *(dst + ofs + l + 0) = *(db + ofs + l + 0 + mvofs);
>> + *(dst + ofs + l + w) = *(db + ofs + l + w + mvofs);
>> + }
>> + }
>> + }
>> + break;
>> + case 0xF7: // copy 8x8 block from src to dest
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 64)
>> + return 1;
>> + for (i = 0; i < 8; i++) {
>> + ofs = i * w;
>> + for (l = 0; l < 8; l++)
>> + *(dst + ofs + l) = bytestream2_get_byteu(&ctx->gb);
>> + }
>> + break;
>> + default: // copy 8x8 block from prev, c37_mv from source
>> + mvofs = c37_mv[opc * 2] + (c37_mv[opc * 2 + 1] * w);
>> + for (i = 0; i < 8; i++) {
>> + ofs = i * w;
>> + for (l = 0; l < 8; l++)
>> + *(dst + ofs + l) = *(db + ofs + l + mvofs);
>> + }
>> + break;
>> + }
>> + return 0;
>> +}
>> +
>> +static int old_codec48(SANMVideoContext *ctx, int width, int height)
>> +{
>> + uint8_t *dst, *prev;
>> + int compr = bytestream2_get_byte(&ctx->gb);
>> + int mvidx = bytestream2_get_byte(&ctx->gb);
>> + int seq = bytestream2_get_le16(&ctx->gb);
>> + uint32_t decoded_size = bytestream2_get_le32(&ctx->gb);
>> + int i, j, flags;
>> +
>> + // all codec48 videos use 1, but just to be safe...
>> + if (mvidx != 1) {
>> + av_log(ctx->avctx, AV_LOG_ERROR, "Invalid motion base value %d.\n", mvidx);
>> + return AVERROR_INVALIDDATA;
>> + }
>> +
>> + bytestream2_skip(&ctx->gb, 4);
>> + flags = bytestream2_get_byte(&ctx->gb);
>> + bytestream2_skip(&ctx->gb, 3);
>> +
>> + if (flags & 8) {
>> + if (bytestream2_get_bytes_left(&ctx->gb) < 0x8080)
>> + return AVERROR_INVALIDDATA;
>> + codec47_read_interptable(ctx);
>> + }
>> +
>> + dst = (uint8_t*)ctx->frm0;
>> + prev = (uint8_t*)ctx->frm2;
>> +
>> + if (!seq) {
>> + ctx->prev_seq = -1;
>> + memset(prev, 0, ctx->aligned_height * width);
>> + }
>> +
>> + switch (compr) {
>> + case 0:
>> + if (bytestream2_get_bytes_left(&ctx->gb) < width * height)
>> + return AVERROR_INVALIDDATA;
>> + for (j = 0; j < height; j++) {
>> + bytestream2_get_bufferu(&ctx->gb, dst, width);
>> + dst += width;
>> + }
>> + break;
>> + case 2:
>> + if (rle_decode(ctx, dst, decoded_size))
>> + return AVERROR_INVALIDDATA;
>> + break;
>> + case 3:
>> + if (seq == ctx->prev_seq + 1) {
>> + for (j = 0; j < height; j += 8) {
>> + for (i = 0; i < width; i += 8) {
>> + if (codec48_block(ctx, dst + i, prev + i, width))
>> + return AVERROR_INVALIDDATA;
>> + }
>> + dst += width * 8;
>> + prev += width * 8;
>> + }
>> + }
>> + break;
>> + case 5:
>> + if (bytestream2_get_bytes_left(&ctx->gb) < ((width + 1) >> 1) * ((height + 1) >> 1))
>> + return AVERROR_INVALIDDATA;
>> + codec47_comp1(ctx, dst, width, height, width);
>> + break;
>> +
>> + default:
>> + avpriv_report_missing_feature(ctx->avctx,
>> + "Subcodec 48 compression %d", compr);
>> + return AVERROR_PATCHWELCOME;
>> + }
>> + ctx->rotate_code = 1; // swap frm[0] and frm[2]
>> + ctx->prev_seq = seq;
>> + return 0;
>> +}
>> +
>> static int process_frame_obj(SANMVideoContext *ctx)
>> {
>> uint16_t codec = bytestream2_get_le16u(&ctx->gb);
>> @@ -1030,6 +1251,8 @@ static int process_frame_obj(SANMVideoContext *ctx)
>> return old_codec37(ctx, top, left, w, h);
>> case 47:
>> return old_codec47(ctx, top, left, w, h);
>> + case 48:
>> + return old_codec48(ctx, w, h);
>> default:
>> avpriv_request_sample(ctx->avctx, "Subcodec %d", codec);
>> return AVERROR_PATCHWELCOME;
>> --
>> 2.47.1
>>
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